RT Journal Article
SR Electronic
T1 The evolutionary basis of premature migration in Pacific salmon highlights the utility of genomics for informing conservation
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 056853
DO 10.1101/056853
A1 Daniel J. Prince
A1 Sean M. O’Rourke
A1 Tasha Q. Thompson
A1 Omar A. Ali
A1 Hannah S. Lyman
A1 Ismail K. Saglam
A1 Thomas J. Hotaling
A1 Adrian P. Spidle
A1 Michael R. Miller
YR 2016
UL http://biorxiv.org/content/early/2016/12/04/056853.abstract
AB The delineation of conservation units (CUs) is a challenging issue that has profound implications for minimizing the loss of biodiversity and ecosystem services. CU delineation typically seeks to prioritize evolutionary significance and genetic methods play a pivotal role in the delineation process by quantifying overall differentiation between populations. While CUs that primarily reflect overall genetic differentiation do protect adaptive differences between distant populations, they do not necessarily protect adaptive variation within highly connected populations. Advances in genomic methodology facilitate the characterization of adaptive genetic variation, but the potential utility of this information for CU delineation is unclear. Here we use genomic methods to investigate the evolutionary basis of premature migration in Pacific salmon, a complex behavioral and physiological adaptation that exists within highly-connected populations and has experienced severe declines. Strikingly, we find that premature migration is associated with the same single locus across multiple populations in each of two different species. Patterns of variation at this locus suggest that the premature migration alleles arose from a single evolutionary event within each species and were subsequently spread to distant populations through straying and positive selection. Our results reveal that complex adaptive variation can depend on rare mutational events at a single locus, demonstrate that CUs reflecting overall genetic differentiation can fail to protect evolutionarily significant variation that has substantial ecological and societal benefits, and suggest that a supplemental framework for protecting specific adaptive variation will sometimes be necessary to prevent the loss of significant biodiversity and ecosystem services.